Preterm birth rate hits 15-year low in U.S.

The rate of premature births in the U.S. dropped for the sixth consecutive year, reaching a 15-year low of 11.5% in 2012, according to a March of Dimes report released Friday. Although six states were given an "A," the country overall earned a "C." If preventive measures were fully implemented, the rate could be as low as 9.6%, the group said.